Variable movement headrest arrangement

ABSTRACT

The present invention involves a vehicle seat and headrest arrangement for use with a seat having a seatback in a vehicle. The vehicle seat and headrest arrangement comprises a headrest arrangement having a headrest. The headrest arrangement has one of a guide member and a follower. The seatback has the other one of a guide member and follower. The guide member has a guideway and the follower engages the guideway of the guide member such that upon impact to the vehicle forward inertia of the headrest will cause the follower to engage the guideway in such a manner as to cause the headrest to move in a manner so as to support the head of an occupant irrespective of whether occupant is in contact with the seatback.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. provisionalapplication Serial Nos. 60/302,016; 60/302,024; and 60/302,019, allfiled on Jun. 29, 2001.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a variable movement headrestarrangement for providing support to the head of an occupant of avehicle upon vehicle impact.

[0004] 2. Background Art

[0005] Improvements in safety mechanisms in the automotive industrycontinue to be made year after year. Such safety mechanisms includesafety headrests. An example of safety seat headrests can be found inViano et al., U.S. Pat. No. 5,378,043, which is incorporated herein byreference. Such safety headrest mechanisms provide support to the headof a vehicle occupant during crash situations.

[0006] More specifically, upon rear impact of a vehicle, the occupant ofthe vehicle compresses into the vehicle seatback, as the head, neck, andtorso move substantially in unison. There typically is greatercompression in the torso and buttocks regions than in the shoulderregion of the occupant. Thus, it has been a concern that the seatbackmay possibly deflect under the torso and buttocks load before the headand neck of the occupant contacts the headrest attached to the seatback.

[0007] Upon front impact of a vehicle, an occupant of the vehicle movesforward relative to the vehicle seatback. Upon contact with a frontinterior panel or a deployed airbag from the front panel, the occupantexperiences rebound movement in a rearward direction. Similar to a rearimpact situation as described above, the occupant in such a situationwould then provide a rearward load into the seatback and compress intothe vehicle seatback, as the head, neck, torso, and buttocks movesubstantially in unison. Thus, in a front impact it is also a concernthat the seatback may possibly deflect under the torso load prior to thehead and neck of the occupant contacting the headrest.

[0008] As a result, safety headrest mechanisms have been designed suchthat, upon impact having rearward movement of a seat occupant, theoccupant's torso contacts an impact target of a vehicle seat with arearward load or force. The impact target is operatively connected to aheadrest or such that, upon the rearward load on the impact target, theheadrest portion moves forward toward the head of the occupant. Theforward movement of the headrest portion in the crash situation lessensthe gap which may exist between the occupant's head and the headrestportion, preventing or lessening the risk of whiplash to the occupant.

[0009] However, it is desirable to have the headrest arrangement moveforward at a high initial velocity in order to decrease the gap betweenthe occupant's head and headrest portion more quickly, but withoutcontacting the occupant's head while moving at the high initialvelocity.

SUMMARY OF THE INVENTION

[0010] It is thus an object of the present invention to provide a costeffective mechanism to support the head of an occupant of a vehicle uponfront and rear vehicle impact.

[0011] In carrying out the above object, and other objects and featuresof this invention, a new vehicle seat and headrest arrangement for usewith a seat having a seatback in a vehicle is provided. The vehicle seatand headrest arrangement comprises a headrest arrangement having aheadrest, the headrest arrangement having one of a guide member and afollower. The seatback has the other one of a guide member and follower.The guide member has a guideway and the follower engaging the guidewayof the guide member such that upon impact to the vehicle, forwardinertia of the headrest will cause the follower to engage the guidewayin such a manner to cause the headrest to move in a manner to supportthe head of an occupant irrespective of whether occupant is in contactwith the seatback.

[0012] In a more specific embodiment, the engagement of the follower andthe guideway of the guide member together with the forward inertia ofthe headrest cause the headrest to move in a first manner and a secondmanner so as to support the head of an occupant.

[0013] In another more specific embodiment, the vehicle seat andheadrest arrangement further includes a damper connected between theheadrest arrangement and the seatback so as to retard movement of theheadrest after it has moved in a manner so as to support the head of anoccupant.

[0014] In another more specific embodiment, the guideway member is abushing having a cam configuration and the follower is a cam such thatengagement of the cam and cam configuration together with the forwardinertia of the headrest cause the headrest to move in a first manner anda second manner.

[0015] In another more specific embodiment, the guideway of the guidemember has a first guideway wall and a second guideway wall and thefollower has a first follower portion and a second follower portionwhich engage the first guideway wall and second guideway wallrespectively to cause the headrest to move in a first manner and asecond manners so as to support the head of an occupant. The secondguideway wall may have a first contact portion and a second contactportion and the second follower portion may have a first surface portionand a second surface portion such that upon impact to the vehicle, thefirst surface portion slidingly engages the first contact portion whilethe first follower portion slidingly engages the first guideway wall soas to cause the headrest to move in a first manner before the secondsurface portion slidingly engages the second contact portion as firstfollower portion continues to slidingly engage the first guideway wallso as to cause the headrest to move in a second manner. The first andsecond contact portions and the first and second surface portions mayhave relatively curved surface configurations and the first guidewaywall and first follower portion may have relatively flat configurationssubstantially parallel to each other and inclined so as to facilitatesliding between the first guideway wall and first follower portion andmovement in the first manner.

[0016] In another more specific embodiment, the headrest arrangementincludes a headrest extension having one of a guideway member and afollower.

[0017] In another more specific embodiment, the vehicle seat andheadrest arrangement further includes a movement-allowing connectorconnected between the headrest arrangement and the seatback.

[0018] In another more specific embodiment, the vehicle seat andheadrest arrangement further includes a biasing member operativelyassociated with the seatback and the headrest arrangement which tends tobias headrest against movement in a manner so as to support the head ofan occupant.

[0019] The vehicle seat and headrest arrangement for use with a seathaving a seatback in a vehicle may also comprise a headrest arrangementincluding a headrest, the headrest arrangement having at least oneimpact target and at least one of a guide member and a follower. Theseatback has the other at least one of a guide member and follower. Theguide member has a guideway and the follower engaging the guideway ofthe guide member such that upon impact to the vehicle one of a rearwardload by the occupant upon the impact target and the forward inertia ofthe headrest irrespective of whether occupant is in contact with theseatback will cause the follower to engage the guideway in such a mannerto cause the headrest to move in a manner to support the head of anoccupant.

[0020] In a more,specific embodiment, the follower engages the guidewayof the guide member such that upon impact to the vehicle the headrestmay be moved in a first manner and a second manner so as to support thehead of an occupant by one of a rearward load by the occupant upon theimpact target and the forward inertia of the headrest irrespective ofwhether occupant is in contact with the seatback.

[0021] In another more specific embodiment, the vehicle seat andheadrest arrangement further includes a damper connected between theheadrest arrangement and the seatback so as to retard movement of theheadrest after it has moved so as to support the head of an occupant.

[0022] In another more specific embodiment, the guide member is abushing having a cam configuration and the follower is a cam such thatengagement of the cam and cam configuration together with the forwardinertia of the headrest cause the headrest to move in a first manner anda second manner.

[0023] In another more specific embodiment, the guideway has a firstguideway wall and a second guideway wall and the follower has a firstfollower portion and a second follower portion which engages the firstguideway wall and second guideway wall respectively to cause theheadrest to move in a first manner and a second manners so as to supportthe head of an occupant. The second guideway wall may have a firstcontact portion and a second contact portion and the second followerportion may have a first surface portion and a second surface portionsuch that upon impact to the vehicle, the first surface portionslidingly engages the first contact portion while the first followerportion slidingly engages the first guideway wall so as to cause theheadrest to move in a first manner before the second surface portionslidingly engages the second contact portion as first follower portioncontinues to slidingly engage the first guideway wall so as to cause theheadrest to move in a second manner. The first and second contactportions and the first and second surface portions may have relativelycurved surface configurations and the first guideway wall and firstfollower portion may have relatively flat configurations substantiallyparallel to each other and inclined so as to facilitate sliding betweenthe first guideway wall and first follower portion and movement in thefirst manner.

[0024] In another more specific embodiment, the vehicle seat andheadrest arrangement further includes a movement-allowing connectorconnected between the headrest arrangement and the seatback.

[0025] In another more specific embodiment, the vehicle seat andheadrest arrangement further includes a biasing member operativelyassociated with the seatback and the headrest arrangement which tends tobias headrest against movement in a manner so as to support the head ofan occupant.

[0026] The vehicle seat and headrest arrangement may also comprise aheadrest arrangement including a headrest and a headrest extension, theheadrest extension having at least one of a guide member and a followerand an impact target located below the at least one of a guide memberand a follower. A seatback frame of the seatback has the other at leastone of a guide member and follower, the guide member having a guidewayand the follower slidingly engaging the guideway of the guide membersuch that upon impact to the vehicle one of a rearward load by theoccupant upon the impact target and the forward inertia of the headrestirrespective of whether occupant is in contact with the seatback willcause the follower to be slidably guided by the guideway such that theheadrest is moved in a first and second manner.

[0027] In another more specific embodiment, the vehicle seat andheadrest arrangement further includes a movement-allowing connectorconnected between the headrest arrangement and the seatback and abiasing member operatively associated with the seatback and the headrestarrangement which tends to bias headrest against movement in a manner soas to support the head of an occupant.

[0028] The vehicle seat and headrest arrangement further includes adamper connected between the headrest arrangement and the seatback so asto retard movement of the headrest after it has moved so as to supportthe head of an occupant.

[0029] In another more specific embodiment, the guide member is fixedlyattached to the seatback frame and has a first guideway wall and asecond guideway wall and the follower is fixedly attached to theheadrest extension and has a first follower portion and a secondfollower portion which slidingly engage the first guideway wall andsecond guideway wall respectively. The second guideway wall may havefirst and second contact portions having relatively curved surfaceconfigurations, the second follower portion may have first and secondsurface portions having relatively curved surface configurations, andthe first guideway wall and first follower portion may have relativelyflat configurations substantially parallel to each other and inclinedrelative to the headrest extension such that upon impact to the vehicle,the first surface portion slidingly engages the first contact portionwhile the first follower portion slidingly engages the first guidewaywall so as to cause the headrest to move in a first manner before thesecond surface portion slidingly engages the second contact portion asthe first follower portion continues to slidingly engage the firstguideway wall so as to cause the headrest to move in a second manner.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is a perspective view of a vehicle seat and headrestarrangement in accordance with the present invention;

[0031]FIG. 2 is a perspective view of a variable pivot mechanism for aheadrest on a seatback frame in accordance with the present invention;

[0032]FIG. 3 is a cross-sectional view of a variable pivot mechanism forthe headrest of FIG. 2 taken along lines 3-3;

[0033]FIG. 4 is a side view of movement of the headrest upon impact inaccordance with the present invention;

[0034]FIG. 5 is a perspective view of another embodiment of the variablepivot mechanism in accordance with the present invention;

[0035]FIG. 6 is a cross-sectional view of the embodiment in FIG. 4 takenalong lines 6-6;

[0036]FIG. 7 is a flow chart of one method of providing head supportwith a movable headrest of a vehicle seat to a vehicle occupant duringrebound from a front impact of the vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0037]FIG. 1 illustrates a vehicle seat and headrest arrangement 10having seat bottom 11 with fore end 11 a and aft end 11 b, seatback 12with seatback frame 13 joined to seat bottom 11 adjacent aft end 11 b,and headrest arrangement 14 pivotally and slidably attached to seatbackframe 13. Headrest arrangement 14 includes moveable headrest 22 which,in this and in most typical embodiments, is cushioned. As will bedescribed in greater detail below, headrest 22 moves variably uponvehicle impact. In the embodiment shown, such variable movement occursin first and second manners wherein the first and second manners relateto first and second forward velocities respectively, those being thevelocities of the headrest 22 forward toward the occupant or the frontof the vehicle, and first and second trajectories respectively, thosebeing the trajectories or paths of headrest 22. Such variable movementcould be along any suitable combination of trajectories and velocities.As long as at least one of the first forward velocity and firsttrajectory is different than one of a second forward velocity and secondtrajectory, movement in first and second manners, variable movement, hasbeen achieved. However, as will be explained in more detail, in theevent of a vehicle impact, it is preferable that the headrest move in afirst manner so as to more quickly lessen the gap between the head of anoccupant and the headrest 22 and move in a second manner so as todecrease the forward velocity and provide support upon contact with theoccupant's head.

[0038] As will be also described in greater detail below, headrest 22 isguidedly or cammingly moved from the normal position to the actuatedposition upon impact and irrespective of, or prior to, the occupantbeing in contact with the seatback 12.

[0039]FIG. 2 depicts headrest arrangement 14 movable with respect toseatback frame 13. As shown, seatback frame 13 includes upper crossmember 16 having ends 17, each of which have a side member 18 integrallyattached thereto and extending downwardly therefrom. Lower cross member20 extends across seatback frame 13 to connect side members 18. Lowercross member 20 may be attached to side members 18 by any suitablemeans, such as by bolts (not shown).

[0040] In this embodiment, the upper cross member 16 includes at leastone guide member, in this embodiment bushings 21. Such bushings may beattached to the cross member 16 or formed within the cross member 16.While not shown, the guide members could also be connected to any partof the seatback frame. Furthermore, the guide members, such as thebushings 21 shown, may be fixedly, rotatably, or otherwise movablyconnected to seatback frame 13 by any suitable means. In thisembodiment, bushings 21 are welded to upper cross member 16.

[0041] As shown, headrest arrangement 14 includes headrest 22 havingcushion frame 23, headrest extension 24 extending downwardly therefrom,and impact target 26 to which extension 24 extends. The impact target 26may have any suitable configuration or shape and may be made from anysuitable material. In this embodiment, impact target 26 is disposedwithin seatback frame 13 and between side members 18. The headrest 22and impact target 26 are operatively associated as the headrestarrangement 14 moves variably with respect to the seat back frame 13. Asdescribed in greater detail below, headrest arrangement 14 cooperateswith seatback frame 13 to define shifting axes about which headrestarrangement 14 pivots.

[0042] As depicted in FIGS. 2 and 3, headrest extension 24 extendsdownwardly from cushion frame 23 through each guide member, in thisembodiment bushings 21, to an impact target 26. Each guide memberdefines a guideway, in this embodiment guideway 25. As shown, theheadrest extension 24 in this embodiment constitutes two posts. However,a single post or any other suitable extension may be utilized. Likewise,a single guide member or any other suitable number of guide members maybe utilized. Furthermore, while not shown the headrest extension of theheadrest arrangement could include or constitute an upper portion orpart of the seatback frame such that the upper portion or part couldmove variably.

[0043] As shown in this embodiment, one or more movement-allowingconnectors 28, such as links or hinges shown, may be used to pivotallyor otherwise suitably attach impact target 26 to side members 18. Suchmovement-allowing connectors 28 may be connected at each end to theimpact target 26 and side member 18 respectively, in a pivotal, fixed,or otherwise suitable manner. More specifically, as shown in theembodiment depicted, each of the movement-allowing connectors 28 may bepivotally attached to the seatback frame 13 on pivot axis A generallyperpendicular to the fore and aft direction. The other end of themovement-allowing connector may also be pivotally attached to the impacttarget 26. As shown in FIGS. 2 and 4, the pivot axis A is offsetrelative to the impact target 26 such that a rearward force applied tothe impact target 26 will tend to cause the movement-allowing connector28 to pivot about the pivot axis A and the impact target to move in agenerally rearward and upward direction. Of course, any other suitablemovement-allowing connector 28 between the impact target 26 and the sidemember 18, or between any suitable portion of the headrest arrangement14 and the seatback frame 13, could be used, such as multiple linkagesfor example, such that the impact target pivots about a fixed orvariable (instantaneous) pivot axis.

[0044] Rearward loading of impact target 26 will cause headrest 22 topivot toward the head of the occupant. Preferably, a suitable biasingmember is operatively associated with the seatback frame 13 and headrestarrangement 14 in order to bias headrest arrangement 14 against suchmovement. As shown in this embodiment, such biasing member may consistof springs 29 attached between the lower cross member 20 and each link28. However, such biasing member may be operatively associated with orbetween the seatback frame 13 and headrest arrangement 14 in anysuitable manner. Furthermore, while in this embodiment, spring 29 is ametallic coil, any suitable biasing member, such as an elastic tube, maybe used.

[0045] As shown in this embodiment, a damper 27 may be connected to theimpact target 26 and the seatback frame 13 for retarding rearwardmovement of headrest 22 as will be described in further detail. Thedamper 27 may be any suitable dampening or biasing material, device, ormechanism which lengthens, expands, or extends under a relatively lightor suitable tensile load while suitably retarding, which may includepreventing, movement under a compressive load. If one or more dampers 27are employed, they may be disposed at any suitable location , and beconnected between the seatback frame 13 or any other suitable component,and the impact target 26, the headrest extension 24, the headrest 22, orany other suitable component in any suitable manner and at any suitablelocation in order to retard rearward movement of headrest 22. Forexample, and without limitation, dampers 27 may be disposed between thelower cross member 20 and links 28.

[0046] As shown in FIG. 3, in one embodiment of the present inventionthe guide member, in this embodiment the bushing 21, includes a guideway25, which in this embodiment includes a cam configuration 31 having afirst movement portion and a second movement portion, the operation ofwhich is described in paragraphs below. While the guideway 25 in thisembodiment has a first movement portion and a second movement portion,the guideway 25 is not limited to such a configuration but may have anysuitable configuration. Furthermore, the guide member could utilize aslot or any other suitable configuration in guiding the follower as willbe explained.

[0047] The cam configuration 31 in this embodiment includes a firstguideway wall 32 and a second guideway wall 34. As shown, secondguideway wall 34 may have first contact portion 36 and second contactportion 38 formed vertically adjacent each other and integrallyconnected. In this embodiment the first guideway wall 32 has arelatively flat surface configuration inclined at an angle relative tothe adjacent portion of the extension 24. The first contact portion 36and second contact portion 38 of the second guideway wall 34 both haverelatively curved or arcuate surface configurations. Of course, anyother suitable configuration of the first and second guideway walls 32,34 may be used. Likewise, any suitable configuration of first and secondcontact portions 36, 38, may be used

[0048] As illustrated in FIG. 3, the follower 39, in this embodiment acam 40, may be disposed on extension 24. Cam 40 may be disposed onextension 24 by any suitable means such as by welding or molding. Thefollower 39, in this embodiment cam 40, cooperates with the guideway 25of the guide member, in this embodiment the bushing 21 having a camconfiguration 31 with a first guideway wall 32 and second guideway wall34. While the follower in this embodiment is a cam, any other suitablefollower configuration could be utilized, such as a projectionprojecting laterally from the extension 24 and engaging a slot or othersuitable configuration of the guide member. Furthermore, while in thisembodiment the follower is connected to the extension 24 and the guidemember is connected to the seatback frame 13, the follower could also beconnected to the seatback frame 13 and the guide member could beconnected to the extension 24.

[0049] The follower, in this embodiment the cam 40, has a first followerportion 41 and a second follower portion 43. The second follower portion43 includes a first surface portion 42 and a second surface portion 44formed vertically adjacent each other and integrally connected. As shownin this embodiment, first and second surface portions 42, 44 may havesimilar arcuate or curved surface configurations. However, any othersuitable configurations of the first and second surface portions 42,44may be used and the configurations of the first and second surfaceportions may be mirror images of each other or different. In theembodiment shown, while extending the first surface portion 42 initiallyat approximately 30 degrees from the extension 24 to cooperate with thefirst contact portion 36 of the second passageway wall 34 has been foundto be satisfactory, any suitable angle may be used.

[0050] As shown, and as discussed in further detail below, in thisembodiment the first and second surface portions 42, 44 slidably contactfirst and second contact portions 36, 38, respectively, to provideimproved head support to the occupant upon vehicle impact. Of course,first surface portion 42 may also slidably contact second contactportion 38 and second surface portion 44 may also slidably contact firstcontact portion 36 without departing from the spirit or scope of thepresent invention.

[0051] As shown in FIGS. 1-4, in this embodiment the first followerportion 41 extends from extension 24 opposite first and second surfaceportions 42, 44, and has a first follower end 47 to slidably contact thefirst guideway wall 32. While the first follower end 47 of the firstfollower portion 41 has been shown in this embodiment to have arelatively flat surface configuration, inclined relative to theextension 24 so as to slidably cooperate with the first passageway wall,any other suitable configuration may be used. During normal use of thevehicle seat and headrest arrangement 10, the first follower portion 41serves to prevent the extension 24 from shifting back and forth, and toprovide a substantially snug fit within the guide member, in thisembodiment the bushing 21.

[0052] However, upon vehicle impact, first and second follower portions41, 43 and first and second guideway walls 32, 34, are configured tocooperate together to move headrest 22 in first and second manners,e.g., first and second forward velocities and first and secondtrajectories of headrest 22. More specifically, upon impact of thevehicle, an occupant of the vehicle provides rearward load on impacttarget 26. In turn, connectors 28 pivot about axis A and the impacttarget 26 moves in a generally rearward and upward direction. As aresult, extension 24 slides upwardly through the guideway 25 of theguide member, in this embodiment the bushing 21, and first surfaceportion 42 slides along first contact portion 36, and first followerportion 41 slides along first guideway wall 32. This movement, movementin the first manner, defines the first forward velocity and firsttrajectory of headrest 22 toward and relative to the occupant's head.This movement also defines the first movement portion. Morespecifically, this movement in the first manner causes the headrest 22of the headrest arrangement 14 to pivot with respect to the seatbackframe 13 along a first trajectory about and above a constant or shiftingaxis. The first trajectory and the force of the impact define a firstforward velocity of the headrest 22 toward the head of the seatoccupant.

[0053] Then, the second surface portion 44 slides along second contactportion 38, as follower portion 41 continues to slide along and pastfirst guideway wall 32. This movement, movement in the second manner,defines the second velocity and second trajectory of headrest 22 towardand relative to the occupant's head. This movement also defines thesecond movement portion. More specifically, this movement in the secondmanner causes the headrest 22 of the headrest arrangement 10 to pivotwith respect to the seatback frame 13 along a second trajectory aboutand above a constant or shifting axis. The second trajectory and theforce of the impact define a second forward velocity of the headrest 22toward the head of the seat occupant.

[0054] Each of the constant or shifting axes is the pivot axis, alsocalled the instant center axis, instantaneous pivot axis, orinstantaneous axis, about which the headrest 22 pivots at any given timeduring movement along a particular trajectory.

[0055] In the embodiments shown, the pivot axis, also called the instantcenter axis, instantaneous pivot axis, or instantaneous axis, aboutwhich the headrest portion pivots shifts throughout the trajectories ofthe headrest 22 during a rearward loading of the impact target. Shiftingthe instantaneous axis downwardly allows the headrest 22 to move in amore forwardly direction toward the occupant's head upon a rearwardforce to the impact target. Preferably, the vehicle seat and headrestarrangement is such that the instantaneous axis shifts within arelatively lower range of positions during camming between the firstsurface portion 42 and the first contact portion 36. The resultingtrajectory is such that the headrest 22 will move in a direction moredirected toward the occupant's head during the course of the firsttrajectory. Shifting the instantaneous axis upwardly, within arelatively higher range of positions, after the movement in the firstmanner has been accomplished, allows the headrest 22 to move moreupwardly, and support the occupant's head, during movement in the secondmanner. In the embodiments shown, the cam is formed such that theinstantaneous axis shifts upwardly upon contact of the second surfaceportion with the second contact portion 38.

[0056] In summary, upon vehicle impact, the headrest 22 moves forwardlyand upwardly in first and second manners, along first and the secondtrajectories, and at first and second forward velocities. The greaterthe crash acceleration, the greater the velocity of headrest 22 in thefirst and second manners.

[0057] Although both trajectories provide for both forward and upwardmovement of the headrest 22, the first trajectory allows the headrest 22to move more forwardly and the second trajectory allows the headrest 22to move more upwardly. The first forward velocity is preferably greaterthan the second forward velocity. The first forward velocity allows theheadrest 22 to quickly move a predetermined distance to lessen the gapbetween the occupant's head and the headrest 22. The second velocityallows the headrest 22 to further lessen the gap and to slow down orstop relative to the seat occupant's head for supporting the occupant'shead upon contact.

[0058] In this particular embodiment, headrest 22 moves in a forward andupward direction for a predetermined distance toward the occupant's headin order to lessen the gap therebetween. More specifically, duringmovement of the headrest 22 in the first and second trajectories, theheadrest 22 is configured to move forward a predetermined distance.While a distance range between 2 and 25 centimeters may be suitable, anysuitable distance may be used and will be dependent, at least in part,on the interior design parameters of the particular vehicle.

[0059] In the particular embodiment shown, due to the configuration ofthe first surface portion 42 and the first contact portion 36, theheadrest 22 moves more forwardly than upwardly to define the firsttrajectory, providing the first forward velocity. Due to theconfiguration of the second surface portion 44 and the second contactportion 38, the headrest 22 moves more upwardly than forwardly to definethe second trajectory, providing the second forward velocity. Thus, inthis embodiment, the first forward velocity is greater then the secondforward velocity in the direction toward the head of the vehicleoccupant. Accordingly, surface portions 44, 46 and contact portions 36,38 are designed to reduce headrest 22 movement directly toward theoccupant's head after movement in the first manner.

[0060] In normal vehicle seat and headrest arrangements, during theinitial stages of an impact, the occupant's torso is in contact with theseatback while the occupant's head is several inches forward of theheadrest 22. This condition is consistent with the body being reclinedat about 20-25 degrees from vertical with the neck being approximatelyvertical. In contrast, the seat is usually at a reclined angle ofapproximately 20-25 degrees from vertical, with the headrest eitherfollowing the inclination of the seatback or curving slightly forward.In any event, for seating comfort, the head is usually not in contactwith the headrest while driving.

[0061] As the occupant loads the seatback in an impact, force builds upbehind the torso and buttocks of the seat occupant as the head, neck,torso, and buttocks move in unison. Typically, there is a greatercompression in the torso and buttocks regions of the seat, with agradual reduction up to the shoulder level as the body remains upright.The more severe the crash, the greater the compression of the occupantinto the seatback. As this action is occurring, the initial load of theoccupant tends to deflect the seatback rearwardly. The amount ofdeflection is related to the bending stiffness of the seatback. Theseatback may possibly deflect under the torso load prior to the head andneck of the occupant contacting the headrest. The current inventionreduces this “whiplash” effect by bringing the headrest forward into ahead supporting position.

[0062] In a front impact of the vehicle, the occupant initially movesforward relative to the vehicle seatback. Upon contact with a frontinterior panel or a deployed airbag from the front panel of the vehicle,the occupant experiences rebound movement in a rearward direction. Asthe occupant loads the seatback in a rebound during the front impact,force builds up behind the torso and buttocks of the occupant. Like arear impact, depending upon the compliance of the seatback, the occupantcompresses into the cushion as the head, neck, and torso move in unison.In this situation, like in a rear impact situation, there is a greatercompression in the buttocks region than in the shoulder region of theoccupant. Thus, there is a potential that the seatback deflects underthe torso load prior to the head and neck of the occupant contacting theheadrest, resulting in a gap between the head and the headrest in afront crash situation and the potential for a “whiplash” effect.

[0063] With the present invention and in the event of a front impact,the sudden substantial deceleration in forward velocity will cause theheadrest 22 to move forward from the normal position, independent of theoccupant contacting the seatback 12 or impact plate 26. Upon frontimpact of the vehicle, when the occupant is initially thrown forward,the forward inertia of the headrest 22 will cause the follower 39 tofollow the guideway 25 such that the first follower end 47 will slidablyengage the first guideway wall 32 while the first surface portion 42slidably engages the first contact portion 36. This allows headrest 22to move at least in the first manner, at the first forward velocity andalong the first trajectory. Then, similar to a rear impact situationdescribed above, the second surface portion 44 will slidably engage thesecond contact portion 38. This allows the headrest 22 to move in thesecond manner, at the second forward velocity and along the secondtrajectory. As in a rear impact situation, the headrest 22 will thenhave moved in a forward direction for a predetermined distance towardthe occupant's head in order to lessen the gap between the headrest andthe occupant's head. The damper 27 serves to retard, which may includepreventing, movement of the headrest back from the actuated or forwardposition back to the non-actuated or normal position before and aftercontact between the occupant's head and the headrest.

[0064]FIGS. 5 and 6 depict another embodiment which operates similar tothe embodiment described above. This embodiment includes componentssimilar to components of vehicle seat and headrest arrangement 10 above.Similar components will be referred to by the same reference charactersused to identify like components in the first embodiment. However, inthis embodiment, a different guide member, bushing 121, is disposed onseatback frame 13 and includes a first guideway wall 132 and secondguideway wall 134 having a pair of first and second contact portions136, 138. A follower, in this embodiment a cam 140, is disposed onextension 124 and includes a pair of first and second surface portions142, 144 formed to cooperate with the pair of first and second contactportions 136, 138, respectively. As shown, the first guideway wall 132includes a planar surface upon which a first follower portion 141 slidesduring movement of the headrest arrangement 114. Similar to theembodiment described above, the first and second surface portions 142,144 slidably contact the first and second contact portions 136, 138,respectively, to define first and second forward velocities and firstand second trajectories of the headrest 22 during vehicle impact and toaccordingly provide improved head support to the occupant upon vehicleimpact.

[0065] While not shown, as a further alternative example embodiment, theinvention may be constructed such that the impact target 26 is notconnected to the side member 18. In such an embodiment, the impacttarget could be supported in the non-impact position via a guide memberand follower for example.

[0066] It is to be noted that the embodiments described above may bemade by any conventional means using any conventional materials known inthe vehicle seating art.

[0067]FIG. 7 depicts one method 310 of supporting the head of a vehicleoccupant in a vehicle seat having a seatback and a headrest arrangementmovable with respect to the seatback. Method 310 includes providing theheadrest adapted to be spaced from the head of the occupant in the seatto define a normal or rest position of the headrest arrangement in block312. In the normal position, an instant center of the headrestarrangement is designed or configured substantially lower relative tothe center of gravity of the headrest arrangement. Thus, upon frontimpact of the vehicle in block 314, the headrest arrangementindependently moves from the normal position toward contact with theoccupant's head in a first manner and a second manner to define anactuated position of the headrest, irrespective of the occupant being incontact with the seatback of the vehicle seat. The configuration of theguideway and the follower allows the headrest to independently moveforward to support the occupant's head upon a front impact in a firstmanner and second manner. As described above, the first manner involvesthe headrest moving along a first trajectory at a first forwardvelocity. The second manner involves the headrest moving along a secondtrajectory at a second forward velocity. In block 316, the methodincludes retarding movement of the headrest arrangement back from theactuated position to the normal position, before and after contact withthe head. The damper retards such movement. This provides improvedsupport to the occupant's head from rebound toward the seatback in thecase of a front impact.

[0068] While embodiments of the invention have been illustrated anddescribed, it is not intended that these embodiments illustrate anddescribe all possible forms of the invention. Rather, the words used inthe specification are words of description rather than limitation, andit is understood that various changes may be made without departing fromthe spirit and scope of the invention.

What is claimed is:
 1. A vehicle seat and headrest arrangement for usewith a seat having a seatback in a vehicle, the vehicle seat andheadrest arrangement comprising: a headrest arrangement having aheadrest, the headrest arrangement having one of a guide member and afollower; the seatback having the other one of a guide member andfollower, the guide member having a guideway and the follower engagingthe guideway of the guide member such that upon impact to the vehicleforward inertia of the headrest will cause the follower to engage theguideway in such a manner as to cause the headrest to move in a mannerso as to support the head of an occupant irrespective of whetheroccupant is in contact with the seatback.
 2. The vehicle seat andheadrest arrangement of claim 1 wherein the engagement of the followerand the guideway of the guide member together with the forward inertiaof the headrest cause the headrest to move in a first manner and asecond manner so as to support the head of an occupant.
 3. The vehicleseat and headrest arrangement of claim 2 further including a damperconnected between the headrest arrangement and the seatback so as toretard movement of the headrest after it has moved in a manner so as tosupport the head of an occupant.
 4. The vehicle seat and headrestarrangement of claim 2 wherein the guideway member is a bushing having acam configuration and the follower is a cam such that engagement of thecam and cam configuration together with the forward inertia of theheadrest cause the headrest to move in a first manner and a secondmanner.
 5. The vehicle seat and headrest arrangement of claim 2 whereinthe guideway of the guide member has a first guideway wall and a secondguideway wall and the follower has a first follower portion and a secondfollower portion which engage the first guideway wall and secondguideway wall respectively to cause the headrest to move in a firstmanner and a second manners so as to support the head of an occupant. 6.The vehicle seat and headrest arrangement of claim 5 wherein the secondguideway wall has a first contact portion and a second contact portionand the second follower portion has a first surface portion and a secondsurface portion such that upon impact to the vehicle, the first surfaceportion slidingly engages the first contact portion while the firstfollower portion slidingly engages the first guideway wall so as tocause the headrest to move in a first manner before the second surfaceportion slidingly engages the second contact portion as first followerportion continues to slidingly engage the first guideway wall so as tocause the headrest to move in a second manner.
 7. The vehicle seat andheadrest arrangement of claim 6 wherein the first and second contactportions and the first and second surface portions have relativelycurved surface configurations and the first guideway wall and firstfollower portion have relatively flat configurations substantiallyparallel to each other and inclined so as to facilitate sliding betweenthe first guideway wall and first follower portion and movement in thefirst manner.
 8. The vehicle seat and headrest arrangement of claim 2wherein the headrest arrangement includes a headrest extension havingone of a guideway member and a follower.
 9. The vehicle seat andheadrest arrangement of claim 2 further including a movement-allowingconnector connected between the headrest arrangement and the seatback.10. The vehicle seat and headrest arrangement of claim 2 furtherincluding a biasing member operatively associated with the seatback andthe headrest arrangement which tends to bias headrest against movementin a manner so as to support the head of an occupant
 11. A vehicle seatand headrest arrangement for use with a seat having a seatback in avehicle, the vehicle seat and headrest arrangement comprising: aheadrest arrangement including a headrest, the headrest arrangementhaving at least one impact target and at least one of a guide member anda follower; the seatback having the other at least one of a guide memberand follower, the guide member having a guideway and the followerengaging the guideway of the guide member such that upon impact to thevehicle one of a rearward load by the occupant upon the impact targetand the forward inertia of the headrest irrespective of whether occupantis in contact with the seatback will cause the follower to engage theguideway in such a manner as to cause the headrest to move in a mannerso as to support the head of an occupant.
 12. The vehicle seat andheadrest arrangement of claim 11 wherein the follower engages theguideway of the guide member such that upon impact to the vehicle theheadrest may be moved in a first manner and a second manner so as tosupport the head of an occupant by one of a rearward load by theoccupant upon the impact target and the forward inertia of the headrestirrespective of whether occupant is in contact with the seatback. 13.The vehicle seat and headrest arrangement of claim 11 further includinga damper connected between the headrest arrangement and the seatback soas to retard movement of the headrest after it has moved so as tosupport the head of an occupant.
 14. The vehicle seat and headrestarrangement of claim 11 wherein the guide member is a bushing having acam configuration and the follower is a cam such that engagement of thecam and cam configuration together with the forward inertia of theheadrest cause the headrest to move in a first manner and a secondmanner.
 15. The vehicle seat and headrest arrangement of claim 11wherein the guideway has a first guideway wall and a second guidewaywall and the follower has a first follower portion and a second followerportion which engage the first guideway wall and second guideway wallrespectively to cause the headrest to move in a first manner and asecond manners so as to support the head of an occupant.
 16. The vehicleseat and headrest arrangement of claim 15 wherein the second guidewaywall has a first contact portion and a second contact portion and thesecond follower portion has a first surface portion and a second surfaceportion such that upon impact to the vehicle, the first surface portionslidingly engages the first contact portion while the first followerportion slidingly engages the first guideway wall so as to cause theheadrest to move in a first manner before the second surface portionslidingly engages the second contact portion as first follower portioncontinues to slidingly engage the first guideway wall so as to cause theheadrest to move in a second manner.
 17. The vehicle seat and headrestarrangement of claim 16 wherein the first and second contact portionsand the first and second surface portions have relatively curved surfaceconfigurations and the first guideway wall and first follower portionhave relatively flat configurations substantially parallel to each otherand inclined so as to facilitate sliding between the first guideway walland first follower portion and movement in the first manner.
 18. Thevehicle seat and headrest arrangement of claim 11 further including amovement-allowing connector connected between the headrest arrangementand the seatback.
 19. The vehicle seat and headrest arrangement of claim11 further including a biasing member operatively associated with theseatback and the headrest arrangement which tends to bias headrestagainst movement in a manner so as to support the head of an occupant.20. A vehicle seat and headrest arrangement for use with a seat having aseatback in a vehicle, the vehicle seat and headrest arrangementcomprising: a headrest arrangement including a headrest and a headrestextension, the headrest extension having at least one of a guide memberand a follower and an impact target located below the at least one of aguide member and a follower; a seatback frame of the seatback having theother at least one of a guide member and follower, the guide memberhaving a guideway and the follower slidingly engaging the guideway ofthe guide member such that upon impact to the vehicle one of a rearwardload by the occupant upon the impact target and the forward inertia ofthe headrest irrespective of whether occupant is in contact with theseatback will cause the follower to be slidably guided by the guidewaysuch that the headrest is moved in a first and second manner.
 21. Thevehicle seat and headrest arrangement of claim 20 further including amovement-allowing connector connected between the headrest arrangementand the seatback and a biasing member operatively associated with theseatback and the headrest arrangement which tends to bias headrestagainst movement in a manner so as to support the head of an occupant.22. The vehicle seat and headrest arrangement of claim 21 furtherincluding a damper connected between the headrest arrangement and theseatback so as to retard movement of the headrest after it has moved soas to support the head of an occupant.
 23. The vehicle seat and headrestarrangement of claim 22 wherein the guide member is fixedly attached tothe seatback frame and has a first guideway wall and a second guidewaywall and the follower is fixedly attached to the headrest extension andhas a first follower portion and a second follower portion whichslidingly engage the first guideway wall and second guideway wallrespectively.
 24. The vehicle seat and headrest arrangement of claim 23wherein the second guideway wall has first and second contact portionshaving relatively curved surface configurations, the second followerportion has first and second surface portions having relatively curvedsurface configurations, and the first guideway wall and first followerportion have relatively flat configurations substantially parallel toeach other and inclined relative to the headrest extension such thatupon impact to the vehicle, the first surface portion slidingly engagesthe first contact portion while the first follower portion slidinglyengages the first guideway wall so as to cause the headrest to move in afirst manner before the second surface portion slidingly engages thesecond contact portion as the first follower portion continues toslidingly engage the first guideway wall so as to cause the headrest tomove in a second manner.